It’s time once again to visit one of our big-screen Marvel Comics superheroes.Returning us to the world that was unofficially introduced in the first “Iron Man” movie, and picking up where “The Avengers” left off, Thor is back in “Thor: The Dark World.” The movie debuted last weekend, grossing an impressive $86.1 million. Not bad for a man in a red cape.When we revisited Tony Stark this summer in “Iron Man 3,” he had a bit of PTSD from the attack on New York in “The Avengers.” On the other hand, Thor (Chris Hemsworth) hasn’t seen his Earthly lady love, Jane Foster (Natalie Portman), in two years. He’s been busy keeping the peace in the otherworldly Nine Realms. He doesn’t call or text her, but he does ask Heimdall (wonderfully reprised by Idris Elba) to keep his all-seeing eyes on her.What Thor doesn’t know is that Jane still has found trouble. She figures into a plot by some Dark Elves, long thought eradicated, who want to drown the universe in darkness. The only person who can help Thor save the world is his half-brother, Loki (ridiculously talented Tom Hiddleston), who completely steals the show. Others in the cast shine as well. Jamie Alexander wows as Sif, Jane’s competition. Rene Russo gets to kick butt one more time as Frigga, mother of Loki and Thor. I do wish Portman and Hemsworth could drum up a little bit more chemistry, though. I did not have high hopes for this film. It’s difficult for a sequel to live up to its predecessor, and in the Marvel Cinematic Universe, we easily can be lured into skipping one of the sequels — there are just so many of them.I’m glad I didn’t skip this one, though. “Thor: The Dark World” is funny and action-packed. I’m a fan!